Development and progress of human resources will not be achieved just with the public and specialized training. Training is expected to cause desired behavioral changes in employees. But investigations indicate that most training programs do not cause desired behavioral changes in employees. This means that employees are not able to transfer their knowledge to the workplace. Overseas research has shown that many factors are effective in training transfer to the workplace. But in evaluation models used in our country, intervening variables including learner’s readiness, motivation, superior support, and transferring plans, etc. that affect learning and transfer processes are remarkably absent. No evaluation model can be valid without the measurement of the effects of intervening variables. The main objective of the present study is to identify key and affecting factors on the transfer of learning in Iran. Due to its nature, this research has been done using qualitative-exploratory method to identify fortors which have key effect in Iran’s texture and in Research and Technology Petrochemical Company. Delphi method has been used and the statistical population includes experts in Research and Technology Petrochemical Company. Regarding the Delphi method and using the purposive sampling, 15 experienced and connoisseur experts are selected as the sample. Delphi implementation process was organized in three stages. The main instruments of data collection were semi-structured and structured questionnaires. Analysis of the data revealed that a total of 18 factors were identified as important factors. These factors were placed into three individual, organizational and educational general categories.